Introduction: Neurosurgeons continually seek opportunities to characterize and prevent negative outcomes following spine surgery. Deep vein thrombosis (DVT) is one complication that significantly increases postoperative morbidity and mortality. While risk factors and incidence of DVTs have been well characterized in the non-operative setting, its incidence in postoperative spine patients is relatively unknown.
Methods: We evaluated all medical records and radiographic data of 1346 consecutive patients who underwent spinal surgery at Duke University from 2008 to 2010 for incidence of venous thromboembolism within 30 days of surgery and documented all demographic, preoperative, operative, and postoperative variables. Associations between postoperative venous thromboembolism and individual risk factors in all patients were determined using logistic regression analysis. Presence of postoperative venous thromboembolism was determined by clinical documentation and Doppler ultrasound of affected vasculature. Patients were stratified into emergent and elective groups and a similar analysis was performed.
Results: Overall, 16 patients (1.2%) had a venous thromboembolism in the 30 days following surgery, 8 patients (0.7%) undergoing elective surgery and 8 patients (4.2%) after emergent surgery (p < 0.05). Overall, multivariate logistic regression demonstrated for emergent surgery that coronary artery disease (OR: 1.11) and postoperative atrial fibrillation (OR: 5.53) were independently associated with increased risk of postoperative venous thromboembolism. When stratified by elective surgery, we found that intraoperative packed RBC transfusion (OR: 1.91), deep surgical site infection (OR: 17.62), and blood loss > 2.0L (OR: 7.59) were associated with increased risk of venous thromboembolism. There were no demographic, preoperative, or intraoperative variables identified as negative predictors of 30-day perioperative venous thromboembolism in either emergent or elective groups.
Conclusions: The present study demonstrates a low incidence of venous thromboembolism following spine surgery. Patients undergoing emergent spine surgery are at significantly greater risk of developing an adverse thromboembolitic event. This study identifies patient factors predictive of postoperative venous thromboembolism, which may aid in discussions of risk assessment and surgical decision-making.
Patient Care: This study characterizes previously unknown rates and risk factors for perioperative venous thromboembolism in the setting of spine surgery. The results from this study will be used to improve patient selection and clinical management for patients at risk for adverse thromboembolic events.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of perioperative venous thromboembolism in the setting of spine surgery, 2) Discuss, in small groups, the demographic, preoperative, and intraoperative risk factors for perioperative venous thromboembolism, 3) Identify an effective treatment options for spine patients who are at high risk for developing perioperative venous thromboembolism